1. Field of the Invention
The present invention relates to wireless sensors. More particularly, the invention comprises a reconfigurable wireless sensor system for use with multiple, interchangeable sensors.
2. Description of the Prior Art
For many years, the need to remotely monitor the status of an electrical/mechanical system, an animal, or a human being has been recognized. Under some circumstances, such as when the person or thing to be monitored is stationary, data may be communicated by means of a hard connection such as a telephone line, dedicated line, fibre channel, or the like. Often, however, the device, animal, or person to be monitored is mobile and the use of such a hard connection is impossible. For this reason, the field of wireless telemetry has developed. By using a radio frequency (RF) link, one-way or, sometimes, two-way data links can be established between a base monitoring/controlling station and a remote mobile unit supporting a remote sensor.
One such hard wired system is described in U.S. Pat. No. 4,455,453, issued to Theodoros G. Parasekvakos, et al. on Jun. 19, 1984. PARASEKVAKOS, et al. utilize a telephone-based system wherein a remote meter (e.g., a gas or electric utility meter) is selectively connected to a telephone line. The remote meter initiates a telephone call to a central complex at a predetermined time. The central complex initiates a hand shaking authentication routine after which, the remote meter transmits identification information along with its collected data. In addition, the central complex uploads the next call back time as well as any other required operating parameter change.
In contradistinction, the multi-sensor, reconfigurable system of the present invention utilizes an RF link, not a telephone connection. A multiplicity of interchangeable sensors are usable with the inventive system unlike the single, dedicated sensor of PARASEKAVOKOS, et al. Multiple, diverse sensors may be piggybacked in the inventive system. The inventive system also includes data storage capability to save monitored data during any lapse in the RF communications link.
Another hard wired system is taught in U.S. Pat. No. 5,200,743, issued Apr. 6, 1993 to Michael J. St. Martin, et al. St. MARTIN, et al. utilize a four-wire communications like to which multiple remote mobile units are connected, each station having a transducer. One pair of the four-wire system is used to communicate individually with the remote mobile units while the second pair is used to receive data from the stations. Each station may be individually addressed by the host and, upon command, each remote mobile unit transmits real-time, analog data to the host.
The inventive multi-sensor, reconfigurable system however, utilizes an RF link, and, unlike St. MARTIN, et al., may have reconfigurable, interchangeable sensor combinations. Each sensor identifies itself to the base station so that appropriate signal conditioning or signal processing and/or data reduction algorithms may be used. The multiple, piggybacked remote sensors of the inventive system utilize backup memory to store data while the data transceiver is, for example, out-of-range with the base station.
U.S. Pat. No. 5,687,175, issued Nov. 11, 1997 to Virgil Maurice Rochester, Jr., et al. teaches an adaptive, time-division multiplexing communication protocol for collecting data from remote sensors equipped with RF transceivers. All remote units xe2x80x9clistenxe2x80x9d for a command from the host, upon which they transmit a unique ID. These unique IDs are used by the host to individually poll each remote unit. When polled, each remote unit a packet of data. Upon receipt of the data packet from the remote unit, the host transmits an acknowledgement packet indicating that the data has been received. Upon receipt of the acknowledgement from the host, the remote unit is set to a stand-by state whereby it will not respond to the host for a predetermined length of time.
The inventive sensor system uses a packet transmission system for essentially continuous communication between a remote transceiver with its multiple, reconfigurable, self-identifying sensors and a base station. No command from the base host station is required to initiate periodic communication between the remote sensors and the base. Each type of sensor connected to the remote unit uniquely identifies itself to the base station and multiple, diverse sensor types may coexist on the same remote unit.
U.S. Pat. No. 5,959,529, issued Sep. 28, 1999 to Karl A. Kail, IV teaches another system for monitoring remote sensors. KAIL""s sensors are carried or worn by a person or animal to be monitored or affixed to an inanimate object. Unlike the inventive system, the KAIL system teaches dedicated, non-interchangeable sensors having a single function, (i.e., to track the location of the person, animal or object to which the remote sensor is attached). The sensors of the inventive system may be varied and may also be piggybacked to allow monitoring more than one condition, substantially simultaneously. KAIL provides no teaching of any backup memory to store data when the remote sensor is out-of-range. Such backup memory is present in the remote sensor system of the instant invention so that data may be stored for later transmission when the communications link is unavailable.
In each one of these prior art inventions, some aspect of remote monitoring is taught, either utilizing a hard (i.e., wired) connection or an RF link. Unlike the prior art, the inventive system supports multiple remote mobile units on the same system, each remote mobile unit being capable of supporting multiple, diverse sensors.
None of the above inventions and patents, taken either singly or in combination, is seen to describe or render obvious the instant invention as claimed.
The present invention features a remote monitor system for a plurality of sensors. A remote mobile unit is equipped with one or more interchangeable sensors, each sensor being capable of providing a unique identity code to the base monitoring station. Multiple sensors may be piggybacked to simultaneously monitor more than one condition or parameter. The inventive system includes routines which automatically recognize each sensor type and invokes specific software routines applicable only to the sensors. This quasi xe2x80x9cplug and playxe2x80x9d approach overcomes problems where improper sensor inputs are made to a particular data analysis routine which often results in apparent sensor data errors. The inventive system is applicable to a wide variety of fields such as biomedical, athletics, security, etc. Each remote mobile unit has provision for both signal conditioning and data processing (i.e., data analysis, data reduction, etc.). In addition, storage is provided at each remote mobile unit so that, in the event that the RF link is unavailable, the sensor data may be stored for later transmission once the RF link is reestablished. In that event that data is being collected at a rate faster than it can be transmitted (i.e., a burst rate), the data may also be stored and transmitted at the slower data link rate.
Accordingly, it is a principal object of the invention to provide a wireless remote sensing apparatus.
It is another object of the invention to provide a wireless remote sensing apparatus which may accommodate a variety of diverse, interchangeable sensors.
It is a further object of the invention to provide a wireless remote sensing apparatus incorporating built-in signal conditioning and signal processing.
Still another object of the invention is to provide a wireless remote sensing apparatus having built-in storage which accumulates data during times when an RF link is unavailable to transmit data to a base station.
It is yet another object of the invention to provide data storage to buffer data being collected at a rate faster than the data can be transmitted to a base station.
An additional object of the invention is to provide a wireless remote sensing apparatus having automatic recognition of the sensor mix present.
It is again an object of the invention to provide a wireless remote sensing apparatus wherein a base station can upload appropriate software modules to the remote based upon the detected mix of sensors.
Yet another object of the invention is to provide a wireless remote sensing apparatus having remote programmability.
It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.